Metabolic switch regulates lineage plasticity and induces synthetic lethality in triple-negative breast cancer

Emerging roles for fatty acid oxidation in cancer

Fatty acid oxidation (FAO) denotes the mitochondrial aerobic process responsible for breaking down fatty acids (FAs) into acetyl-CoA units. This process holds a central position in the cancer metabolic landscape, with certain tumor cells relying primarily on FAO for energy production. Over the past decade, mounting evidence has underscored the critical role of FAO in various cellular processes such as cell growth, epigenetic modifications, tissue-immune homeostasis, cell signal transduction, and more. FAO is tightly regulated by multiple evolutionarily conserved mechanisms, and any dysregulation can predispose to cancer development. In this view, we summarize recent findings to provide an updated understanding of the multifaceted roles of FAO in tumor development, metastasis, and the response to cancer therapy. Additionally, we explore the regulatory mechanisms of FAO, laying the groundwork for potential therapeutic interventions targeting FAO in cancers within the metabolic landscape.

Computational modeling of cancer cell metabolism along the catabolic-anabolic axes

Abnormal metabolism is a hallmark of cancer, this was initially recognized nearly a century ago through the observation of aerobic glycolysis in cancer cells. Mitochondrial respiration can also drive tumor progression and metastasis. However, it remains largely unclear the mechanisms by which cancer cells mix and match different metabolic modalities (oxidative/reductive) and leverage various metabolic ingredients (glucose, fatty acids, glutamine) to meet their bioenergetic and biosynthetic needs. Here, we formulate a phenotypic model for cancer metabolism by coupling master gene regulators (AMPK, HIF-1, MYC) with key metabolic substrates (glucose, fatty acids, and glutamine). The model predicts that cancer cells can acquire four metabolic phenotypes: a catabolic phenotype characterized by vigorous oxidative processes-O, an anabolic phenotype characterized by pronounced reductive activities-W, and two complementary hybrid metabolic states-one exhibiting both high catabolic and high anabolic activity-W/O, and the other relying mainly on glutamine oxidation-Q. Using this framework, we quantified gene and metabolic pathway activity by developing scoring metrics based on gene expression. We validated the model-predicted gene-metabolic pathway association and the characterization of the four metabolic phenotypes by analyzing RNA-seq data of tumor samples from TCGA. Strikingly, carcinoma samples exhibiting hybrid metabolic phenotypes are often associated with the worst survival outcomes relative to other metabolic phenotypes. Our mathematical model and scoring metrics serve as a platform to quantify cancer metabolism and study how cancer cells adapt their metabolism upon perturbations, which ultimately could facilitate an effective treatment targeting cancer metabolic plasticity.

SLC7A5/E2F1/PTBP1/PKM2 axis mediates progression and therapy effect of triple-negative breast cancer through the crosstalk of amino acid metabolism and glycolysis pathway

Triple-negative breast cancer (TNBC) is one of the most challenging malignancies with the highest mortality rates among women. TNBC relies on both amino acid metabolism and glycolysis to fuel its bioenergetic and biosynthetic demands. However, the potential crosstalk between these two metabolic pathways and its impact on TNBC progression remain largely unexplored. In this study, we observed that SLC7A5, a key amino acid transporter, was upregulated in TNBC and strongly associated with poor patient prognosis. We demonstrated that the elevated SLC7A5 expression activated the amino acid pathway and promoted cell proliferation, tumor growth, and therapeutic resistance by inducing the switch from PKM1 to PKM2 expression, thereby mediating the crosstalk between amino acid metabolism and glycolysis. We further identified that the upregulation of SLC7A5 resulted from miR-152 suppression, which regulates TNBC cellular function and tumor growth. In addition, the miR-152/SLC7A5 axis mediated the expression of PTBP1, which maintains the balance between PKM1 and PKM2, linking amino acid signaling with the glycolysis pathway. To further understand the mechanism of PTBP1 upregulation, we identified that E2F1 transcriptionally activated PTBP1 expression through direct binding at the seed site, while E2F1 expression was also induced by SLC7A5 in TNBC. This novel SLC7A5/E2F1/PTBP1 axis plays a crucial role in regulating the crosstalk between amino acid signaling and glycolysis in TNBC and is essential for TNBC progression and therapeutic effectiveness. Our findings offer valuable insights into the molecular mechanisms underlying TNBC metabolic reprogramming and highlight potential targets for future therapeutic interventions.

Multilayer cascade-response nanoplatforms as metabolic symbiotic disruptors to reprogram the immunosuppressive microenvironment

Nanomedicine is extensively utilized in tumor treatment, however, the restricted permeability of nanomaterials within tumor tissues, along with the inherent metabolic complexity of these tissues, have hindered effective control of tumor progression. Hypoxic and normoxic tumor cells utilize monocarboxylic acid transporters (MCTs) for the rapid reutilization of lactate, facilitating accelerated tumor growth. Here, cascade-response nanoplatforms (NPs) with contrast-enhanced ultrasound imaging (CEUI) capability had been established, incorporating basigin siRNA internally and featuring hyaluronidase (HAase) and γ-glutamyltranspeptidase (GGT)-responsive lipid coatings externally (GHB NPs). The GHB NPs took advantage of GGT-responsive HAase release to facilitate deep tumor penetration. Furthermore, ultrasound (US) irradiation decreased the expression of glycolysis-related proteins through the modulation of the β-catenin/c-Myc pathway, and US irradiation induced mitochondrial damage, leading to a low-energy state in tumor cells. On this basis, GHB NPs was paired with US stimulation to provide a combination therapy that disturbed tumor cell metabolic symbiosis and remodeled the immunosuppressive tumor microenvironment. This study formulates an effective therapeutic approach for metabolic-immunotherapy, potentially offering a viable candidate for tumor treatment.

Role, mechanisms and effects of Radix Bupleuri in anti‑breast cancer (Review)

The prevalence of breast cancer among women has led to a growing need for innovative anti-breast cancer medications and an in-depth investigation into their molecular mechanisms of action, both of which are essential tactics in clinical intervention. In the clinical practice of Traditional Chinese Medicine, Radix Bupleuri and its active components have shown promise as potential anti-breast cancer agents due to their ability to target multiple pathways, exhibit synergistic effects and reduce toxicity. These compounds are considered to enhance the prognosis of patients with cancer, prolong survival and combat chemotherapy resistance. The present review aimed to delve into the anti-breast cancer properties of Radix Bupleuri and its active ingredients, highlighting their mechanisms, such as inhibition of cell proliferation, promotion of apoptosis, metastasis prevention, microenvironment improvement and synergy with certain chemotherapeutic agents. These findings may provide a scientific rationale for combining Radix Bupleuri and its active components with traditional chemotherapy agents for the management of breast cancer.

The multiple functions and mechanisms of long non-coding RNAs in regulating breast cancer progression

Breast cancer (BC) is a malignant tumor that has the highest morbidity and mortality rates in the female population, and its high tendency to metastasize is the main cause of poor clinical prognosis. Long non-coding RNAs (lncRNAs) have been extensively documented to exhibit aberrant expression in various cancers and influence tumor progression via multiple molecular pathways. These lncRNAs not only modulate numerous aspects of gene expression in cancer cells, such as transcription, translation, and post-translational modifications, but also play a crucial role in the reprogramming of energy metabolism by regulating metabolic regulators, which is particularly significant in advanced BC. This review examines the characteristics and mechanisms of lncRNAs in regulating BC cells, both intracellularly (e.g., cell cycle, autophagy) and extracellularly (e.g., tumor microenvironment). Furthermore, we explore the potential of specific lncRNAs and their regulatory factors as molecular markers and therapeutic targets. Lastly, we summarize the application of lncRNAs in the treatment of advanced BC, aiming to offer novel personalized therapeutic options for patients.

Increasing cisplatin exposure promotes small-cell lung cancer transformation after a shift from glucose metabolism to fatty acid metabolism

OBJECTIVES

Lung cancer is a leading cause of global cancer mortality. Clinical observations reveal that histological transformation from non-small cell lung cancer (NSCLC) to small cell lung cancer (SCLC) is accompanied by mutations in TP53 and RB1. By applying gradually increasing cisplatin concentrations to mimic the escalating drug pressure within the tumor microenvironment, this study investigated the link between phenotypic transformation to SCLC in cisplatin-resistant human lung adenocarcinoma cells and alterations in cellular energy production pathways.

MATERIALS AND METHODS

We established two cisplatin-resistant NSCLC cell lines with varying resistance levels. RNAseq analyses identified TP53 and RB1 gene mutations. Comprehensive functional assays were performed to characterize A549/DDP1 μg/mL and A549/DDP3 μg/mL cells, focusing on proliferation and migratory capabilities. Cellular bioenergetics were assessed through glycolysis and oxidative phosphorylation analyses. Western blotting was employed to examine epithelial-mesenchymal transition (EMT), glucose metabolism, and lipid metabolism markers. Cell cycle distribution was analyzed by flow cytometry. Additionally, a xenograft mouse model was developed for in vivo validation.

RESULTS

TP53 and RB1 mutations were associated with cisplatin concentration-dependent phenotypic transformation, with A549/DDP cells acquiring a more aggressive SCLC-like phenotype (In the article we call the A549/DDPSCLC cells). Analysis of cell bioenergetics profiling and Western blot analyses revealed enhanced glucose metabolism in A549/DDP1 μg/mL cells, while A549/DDPSCLC cells exhibited predominant lipid metabolism. Compound3K and Etomoxir specifically inhibit the activity of PKM2 and CPT1A, respectively, with Etomoxir demonstrating substantially inhibited A549/DDPSCLC cells growth and more cell cycle arrest in the G0/G1 phase. Combinatorial of Compound3K and Etomoxir effectively induced cell death in A549/DDPSCLC phenotype cells in vitro. Etomoxir alone or combined with Compound3K significantly inhibited tumor growth in vivo, with enhanced efficacy in the combination group.

CONCLUSIONS

This study provides the first evidence of cisplatin concentration-dependent metabolic reprogramming during NSCLC-to-SCLC transformation. We identified a phenotypic transition from NSCLC to SCLC accompanied by a metabolic shift from glucose to fatty acid metabolism, offering new insights into therapeutic strategies for treatmentresistant lung cancer.

Comprehensive review of the expanding roles of the carnitine pool in metabolic physiology: beyond fatty acid oxidation

Traditionally, the carnitine pool is closely related to fatty acid metabolism. However, with increasing research, the pleiotropic effects of the carnitine pool have gradually emerged. The purpose of this review is to comprehensively investigate of the emerging understanding of the pleiotropic role of the carnitine pool, carnitine/acylcarnitines are not only auxiliaries or metabolites of fatty acid oxidation, but also play more complex and diverse roles, including energy metabolism, mitochondrial homeostasis, epigenetic regulation, regulation of inflammation and the immune system, tumor biology, signal transduction, and neuroprotection. This review provides an overview of the complex network of carnitine synthesis, transport, shuttle, and regulation, carnitine/acylcarnitines have the potential to be used as communication molecules, biomarkers and therapeutic targets for multiple diseases, with profound effects on intercellular communication, metabolic interactions between organs and overall metabolic health. The purpose of this review is to comprehensively summarize the multidimensional biological effects of the carnitine pool beyond its traditional role in fatty acid oxidation and to summarize the systemic effects mediated by carnitine/acylcarnitine to provide new perspectives for pharmacological research and treatment innovation and new strategies for the prevention and treatment of a variety of diseases.

SIRT3-PINK1-PKM2 axis prevents osteoarthritis via mitochondrial renewal and metabolic switch

Maintaining mitochondrial homeostasis is critical for preserving chondrocyte physiological conditions and increasing resistance against osteoarthritis (OA). However, the underlying mechanisms governing mitochondrial self-renewal and energy production remain elusive. In this study, we demonstrated mitochondrial damage and aberrant mitophagy in OA chondrocytes. Genetically overexpressing PTEN-induced putative kinase 1 (PINK1) protects against cartilage degeneration by removing defective mitochondria. PINK1 knockout aggravated cartilage damage due to impaired mitophagy. SIRT3 directly deacetylated PINK1 to promote mitophagy and cartilage anabolism. Specifically, PINK1 phosphorylated PKM2 at the Ser127 site, preserving its active tetrameric form. This inhibited nuclear translocation and the interaction with β-catenin, resulting in a metabolic shift and increased energy production. Finally, a double-knockout mouse model demonstrated the role of the SIRT3-PINK1-PKM2 axis in safeguarding the structural integrity of articular joints and improving motor functions. Overall, this study provides a novel insight into the regulation of mitochondrial renewal and metabolic switches in OA.

Decomposable STING nanoagonist-amplified oncolytic virotherapy through remodeling the immunosuppressive microenvironment of triple-negative breast cancer

Oncolytic viruses (OVs) are promising for cancer treatment as they specifically replicate in tumor cells. However, the systemic delivery of OVs still faces the challenges of poor tumor targeting, short circulation periods, and limited lytic efficacy. Herein, an OV-concealed targeting nanoagonist (OV-MnO2/HE) was prepared to enhance the delivery of OVs to triple-negative breast cancer (TNBC) via intravenous administration. Decomposable MnO2 biomineral shells covered the surface antigens of OVs to prevent their clearance after systemic administration. The targeting materials of HA-EGCG (HE) enhanced intratumoral accumulation via active targeting. After entering tumors, OV-MnO2/HE readily released Mn2+ and OVs, which could enhance the number of CD4+/CD8+ T cells and maturation dendritic cells (DCs) due to the synergetic effect of the STING pathway and OVs, thereby activating the immune response, resulting in the significant inhibition of TNBC growth. This work highlights the potential of the STING agonist in enhancing the antitumor efficacy of OVs and provides a potent platform for TNBC therapy.

PKM2 knockout facilitates the activation of the AMPK/KLF4/ACADVL pathway, leading to increased oxidative degradation of fatty acids in TNBC

This study unveils PKM2 as a master metabolic coordinator in triple-negative breast cancer (TNBC), governing the glycolysis-lipolysis balance through the AMPK/KLF4/ACADVL axis. We demonstrate stage-specific PKM2 upregulation in TNBC, with CRISPR/Cas9 knockout inducing dual metabolic reprogramming-suppressed glycolysis and activated lipid catabolism. Mechanistically, PKM2 ablation triggers AMPK-dependent nuclear translocation of KLF4, which directly activates ACADVL (mitochondrial β-oxidation rate-limiting enzyme), explaining lipid droplet depletion. Therapeutically, synergistic lethality emerges from combining PKM2 knockout with ACADVL inhibition, suggesting metabolic redundancy disruption strategies. Unlike PKM2-SCAP-mediated lipogenesis reported elsewhere, our work establishes a KLF4-driven lipid catabolic pathway specific to TNBC. Crucially, this AMPK/KLF4/ACADVL network operates independently of BRCA status, proposing targeted therapy for chemoresistant non-BRCA mutant TNBC. Our findings redefine TNBC metabolic plasticity through transcriptional-metabolic crosstalk, offering combinatorial therapeutic paradigms against metabolic adaptation.

Metabolic expression profiling analysis reveals pyruvate-mediated EPHB2 upregulation promotes lymphatic metastasis in head and neck squamous cell carcinomas

Lymphatic metastasis is a well-known factor for initiating distant metastasis of head and neck squamous cell carcinoma (HNSCC), which caused major death in most patients with cancer. Meanwhile, metabolic reprogramming to support metastasis is regarded as a prominent hallmark of cancers. However, how metabolic disorders drive in HNSCC remains unclear. We firstly established a new classification of HNSCC patients based on metabolism gene expression profiles from the TCGA and GEO database, and identified an enriched carbohydrate metabolism subgroup which was significantly associated with lymphatic metastasis and worse clinical outcome. Moreover, we found that highly activated pyruvate metabolism endowed tumors with EPHB2 upregulation and promoted tumor lymphangiogenesis independently of VEGF-C/VEGFR3 signaling pathway. Mechanically, high nuclear acetyl-CoA production from pyruvate metabolism promoted histone acetylation, which in turn transcriptionally upregulated EPHB2 expression and secretion in tumor cells. EPHB2 bound with EFNB1 in lymphatic endothelial cells promoted YAP/TAZ cytoplasmic retention, which alleviated YAP/TAZ-mediated prospero homeobox protein 1 (PROX1) transcriptional repression, and then triggered tumor lymphangiogenesis. Importantly, combined treatment with EFNB1-Fc and VEGFR3 inhibitor synergistic abrogated lymphangiogenesis in vitro and in vivo, suggesting that targeting EPHB2 might be a potential strategy to patients with no or slight response to VEGFR3 inhibitor. These findings uncover the mechanism by which pyruvate metabolism is linked to lymphatic metastasis of tumor and provides a promising therapeutic strategy for the prevention of HNSCC metastasis.

NONO interacts with nuclear PKM2 and directs histone H3 phosphorylation to promote triple-negative breast cancer metastasis

BACKGROUND

Emerging evidence has revealed that PKM2 has oncogenic functions independent of its canonical pyruvate kinase activity, serving as a protein kinase that regulates gene expression. However, the mechanism by which PKM2, as a histone kinase, regulates the transcription of genes involved in triple-negative breast cancer (TNBC) metastasis remains poorly understood.

METHODS

We integrated cellular analysis, including cell viability, proliferation, colony formation, and migration assays; biochemical assays, including protein interaction studies and ChIP; clinical sample analysis; RNA-Seq and CUT&Tag data; and xenograft or mammary-specific gene knockout mouse models, to investigate the epigenetic modulation of TNBC metastasis via NONO-dependent interactions with nuclear PKM2.

RESULTS

We report that the transcription factor NONO directly interacts with nuclear PKM2 and directs PKM2-mediated phosphorylation of histone H3 at threonine 11 (H3T11ph) to promote TNBC metastasis. We show that H3T11ph cooperates with TIP60-mediated acetylation of histone H3 at lysine 27 (H3K27ac) to activate SERPINE1 expression and to increase the proliferative, migratory, and invasive abilities of TNBC cells in a NONO-dependent manner. Conditional mammary loss of NONO or PKM2 markedly suppressed SERPINE1 expression and attenuated the malignant progression of spontaneous mammary tumors in mice. Importantly, elevated expression of NONO or PKM2 in TNBC patients is positively correlated with SERPINE1 expression, enhanced invasiveness, and poor clinical outcomes.

CONCLUSION

These findings revealed that the NONO-dependent interaction with nuclear PKM2 is key for the epigenetic modulation of TNBC metastasis, suggesting a novel intervention strategy for treating TNBC.

Dual targeting PPARα and NPC1L1 metabolic vulnerabilities blocks tumorigenesis

Dysregulated lipid metabolism is linked to tumor progression. In this study, we identified Niemann-Pick C1-like 1 (NPC1L1) as a downstream effector of PKM2. In breast cancer cells, PKM2 knockout (KO) enhanced NPC1L1 expression while downregulating peroxisome proliferator-activated receptor α (PPARα) signaling pathway. PPARα and nuclear factor-E2 p45-related factor 1/2(Nrf1/2) are transcription factors regulating NPC1L1. In vitro PKM2 KO enhanced recruitment of Nrf1/2 to the NPC1L1 promoter region. Fenofibrate, a PPARα activator, promoted NPC1L1 expression; ezetimibe, an NPC1L1 inhibitor and effective Nrf2 activator, also elevated NPC1L1 expression. Combined administration of fenofibrate and ezetimibe significantly induced cytoplasmic vacuolation, and cell apoptosis. Mechanistically, this combined administration activated inositol required enzyme 1α(IRE1α) and produced the spliced form of X-box binding protein (XBP1s), which in turn enhanced lysine demethylase 6B (KDM6B) transcription. XBP1s interacts with KDM6B to activate genes involved in the unfolded protein response by demethylating di- and tri-methylated lysine 27 of histone H3 (H3K27), consequently increasing H3K27 acetylation levels in breast cancer cell lines. Fenofibrate and ezetimibe synergistically inhibited tumor growth in vivo. Our findings reveal that dual targeting of PPARα and NPC1L1 may represent a novel therapeutic regimen for breast cancer therapy.

Design, synthesis and biological evaluation of new SIRT3 activators for the treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) represents a highly malignant subtype of breast cancer with limited therapeutic options. In this study, we designed and synthesized a series of 1,4-DHP derivatives by structure-based strategy, 43 was documented to be a potent SIRT3 activator and exhibited profound anti-proliferative activity in BT-549 and MDA-MB-231 cells with low toxicity over normal cells. Additionally, 43 displayed the ability of direct binding to SIRT3 with a Kd value of 51.51 μM in BLI assay, and the potential bonding mode was elucidated through molecular docking. 43 could inhibit the proliferation, migration, and glycolysis, induced mitochondrial membrane potential decreased and apoptosis in BT-549 and MDA-MB-231 cells. Collectively, these results demonstrate that 43 is a potent SIRT3 activator with the potential to anti-TNBC through signaling pathways regulated by SIRT3.

Stemness of Cancer: A Study of Triple-negative Breast Cancer From a Neuroscience Perspective

Stemness, giving cancer cells massive plasticity enabling them to survive in dynamic (e.g. hypoxic) environments and become resistant to treatment, especially chemotherapy, is an important property of aggressive tumours. Here, we review some essentials of cancer stemness focusing on triple-negative breast cancer (TNBC), the most aggressive form of all breast cancers. TNBC cells express a range of genes and mechanisms associated with stemness, including the fundamental four "Yamanaka factors". Most of the evidence concerns the transcription factor / oncogene c-Myc and an interesting case is the expression of the neonatal splice variant of voltage-gated sodium channel subtype Nav1.5. On the whole, measures that reduce the stemness make cancer cells less aggressive, reducing their invasive/metastatic potential and increasing/restoring their chemosensitivity. Such measures include gene silencing techniques, epigenetic therapies as well as novel approaches like optogenetics aiming to modulate the plasma membrane voltage. Indeed, simply hyperpolarizing their membrane potential can make stem cells differentiate. Finally, we give an overview of the clinical aspects and exploitation of cancer/TNBC stemness, including diagnostics and therapeutics. In particular, personalised mRNA-based therapies and mechanistically meaningful combinations are promising and the emerging discipline of 'cancer neuroscience' is providing novel insights to both fundamental issues and clinical applications.

FOSL1 transcriptionally dictates the Warburg effect and enhances chemoresistance in triple-negative breast cancer

BACKGROUND

Dysregulated energy metabolism has emerged as a defining hallmark of cancer, particularly evident in triple-negative breast cancer (TNBC). Distinct from other breast cancer subtypes, TNBC exhibits heightened glycolysis and aggressiveness. However, the transcriptional mechanisms of aerobic glycolysis in TNBC remains poorly understood.

METHODS

The Cancer Genome Atlas (TCGA) cohort was utilized to identify genes associated with glycolysis. The role of FOSL1 in glycolysis and tumor growth in TNBC cells was confirmed through both loss-of-function and gain-of-function experiments. The subcutaneous xenograft model was established to evaluate the therapeutic potential of targeting FOSL1 in TNBC. Additionally, chromatin immunoprecipitation and luciferase reporter assays were employed to investigate the transcriptional regulation of glycolytic genes mediated by FOSL1.

RESULTS

FOSL1 is identified as a pivotal glycolysis-related transcription factor in TNBC. Functional verification shows that FOSL1 enhances the glycolytic metabolism of TNBC cells, as evidenced by glucose uptake, lactate production, and extracellular acidification rates. Notably, FOSL1 promotes tumor growth in TNBC in a glycolysis-dependent manner, as inhibiting glycolysis with 2-Deoxy-D-glucose markedly diminishes the oncogenic effects of FOSL1 in TNBC. Mechanistically, FOSL1 transcriptionally activates the expression of genes such as SLC2A1, ENO1, and LDHA, which further accelerate the glycolytic flux. Moreover, FOSL1 is highly expressed in doxorubicin (DOX)-resistant TNBC cells and clinical samples from cases of progressive disease following neoadjuvant chemotherapy. Targeting FOSL1 proves effective in overcoming chemoresistance in DOX-resistant MDA-MB-231 cells.

CONCLUSION

In summary, FOSL1 establishes a robust link between aerobic glycolysis and carcinogenesis, positioning it as a promising therapeutic target, especially in the context of TNBC chemotherapy.

ARMH1 is a novel marker associated with poor pediatric AML outcomes that affect the fatty acid synthesis and cell cycle pathways

Introduction

Despite remarkable progress in Pediatric Acute Myeloid Leukemia (pAML) treatments, the relapsed disease remains difficult to treat, making it pertinent to identify novel biomarkers of prognostic/therapeutic significance.

Material and methods

Bone marrow samples from 21 pAML patients were analyzed using single cell RNA sequencing, functional assays with ARMH1 knockdown and overexpression were performed in leukemia cell lines to evaluate impact on proliferation and migration, and chemotherapy sensitivity. Mitochondrial function was assessed via Seahorse assay, ARMH1 interacting proteins were studied using co-immunoprecipitation. Bulk RNA-seq was performed on ARMH1knockdown and over expressing cell lines to evaluate the pathways and networks impacted by ARMH1.

Results

Our data shows that ARMH1, a novel cancer-associated gene, is highly expressed in the malignant blast cells of multiple pediatric hematologic malignancies, including AML, T/B-ALL, and T/B-MPAL. Notably, ARMH1 expression is significantly elevated in blast cells of patients who relapsed or have a high-risk cytogenetic profile (MLL) compared to standard-risk (RUNX1, inv (16)). ARMH1 expression is also significantly correlated with the pediatric leukemia stem cell score of 6 genes (LSC6) associated with poor outcomes. Perturbation of ARMH1 (knockdown and overexpression) in leukemia cell lines significantly impacted cell proliferation and migration. The RNA-sequencing analysis on multiple ARMH1 knockdown and overexpressing cell lines established an association with mitochondrial fatty acid synthesis and cell cycle pathways.The investigation of the mitochondrial matrix shows that pharmacological inhibition of a key enzyme in fatty acid synthesis regulation, CPT1A, resulted in ARMH1 downregulation. ARMH1 knockdown also led to a significant reduction in CPT1A and ATP production as well as Oxygen Consumption Rate. Our data indicates that downregulating ARMH1 impacts cell proliferation by reducing key cell cycle regulators such as CDCA7 and EZH2. Further, we also established that ARMH1 is a key physical interactant of EZH2, associated with multiple cancers.

Conclusion

Our findings underscore further evaluation of ARMH1 as a potential candidate for targeted therapies and stratification of aggressive pAML to improve outcomes.

PKM2-Driven Lactate Overproduction Triggers Endothelial-To-Mesenchymal Transition in Ischemic Flap via Mediating TWIST1 Lactylation

The accumulation of lactate is a rising risk factor for patients after flap transplantation. Endothelial-to-mesenchymal transition (EndoMT) plays a critical role in skin fibrosis. Nevertheless, whether lactate overproduction directly contributes to flap necrosis and its mechanism remain unknown. The current study reveals that skin flap mice exhibit enhanced PKM2 and fibrotic response. Endothelial-specific deletion of PKM2 attenuates flap necrosis and ameliorates flap fibrosis in mice. Administration of lactate or overexpressing PKM2 promotes dysfunction of endothelial cells and stimulates mesenchymal-like phenotype following hypoxia. Mechanistically, glycolytic-lactate induces a correlation between Twist1 and p300/CBP, leading to lactylation of Twist1 lysine 150 (K150la). The increase in K150la promotes Twist1 phosphorylation and nuclear translocation and further regulates the transcription of TGFB1, hence inducing fibrosis phenotype. Genetically deletion of endothelial-specific PKM2 in mice diminishes lactate accumulation and Twist1 lactylation, then attenuates EndoMT-associated fibrosis following flap ischemia. The serum lactate levels of flap transplantation patients are elevated and exhibit predictive value for prognosis. This findings suggested a novel role of PKM2-derived lactate in mediating Twist1 lactylation and exacerbates flap fibrosis and ischemia. Inhibition of glycolytic-lactate and Twist1 lactylation reduces flap necrosis and fibrotic response might become a potential therapeutic strategy for flap ischemia.

Metabolic reprogramming and therapeutic resistance in primary and metastatic breast cancer

Metabolic alterations, a hallmark of cancer, enable tumor cells to adapt to their environment by modulating glucose, lipid, and amino acid metabolism, which fuels rapid growth and contributes to treatment resistance. In primary breast cancer, metabolic shifts such as the Warburg effect and enhanced lipid synthesis are closely linked to chemotherapy failure. Similarly, metastatic lesions often display distinct metabolic profiles that not only sustain tumor growth but also confer resistance to targeted therapies and immunotherapies. The review emphasizes two major aspects: the mechanisms driving metabolic resistance in both primary and metastatic breast cancer, and how the unique metabolic environments in metastatic sites further complicate treatment. By targeting distinct metabolic vulnerabilities at both the primary and metastatic stages, new strategies could improve the efficacy of existing therapies and provide better outcomes for breast cancer patients.

Metabolism and epigenetics: drivers of tumor cell plasticity and treatment outcomes

Emerging evidence indicates that metabolism not only is a source of energy and biomaterials for cell division but also acts as a driver of cancer cell plasticity and treatment resistance. This is because metabolic changes lead to remodeling of chromatin and reprogramming of gene expression patterns, furthering tumor cell phenotypic transitions. Therefore, the crosstalk between metabolism and epigenetics seems to hold immense potential for the discovery of novel therapeutic targets for various aggressive tumors. Here, we highlight recent discoveries supporting the concept that the cooperation between metabolism and epigenetics enables cancer to overcome mounting treatment-induced pressures. We discuss how specific metabolites contribute to cancer cell resilience and provide perspective on how simultaneously targeting these key forces could produce synergistic therapeutic effects to improve treatment outcomes.

Mechanisms governing lineage plasticity and metabolic reprogramming in cancer

Dynamic alterations in cellular phenotypes during cancer progression are attributed to a phenomenon known as 'lineage plasticity'. This process is associated with therapeutic resistance and involves concurrent shifts in metabolic states that facilitate adaptation to various stressors inherent in malignant growth. Certain metabolites also serve as synthetic reservoirs for chromatin modification, thus linking metabolic states with epigenetic regulation. There remains a critical need to understand the mechanisms that converge on lineage plasticity and metabolic reprogramming to prevent the emergence of lethal disease. This review attempts to offer an overview of our current understanding of the interplay between metabolic reprogramming and lineage plasticity in the context of cancer, highlighting the intersecting drivers of cancer hallmarks, with an emphasis on solid tumors.

Cancer metabolic reprogramming and precision medicine-current perspective

Despite the advanced technologies and global attention on cancer treatment strategies, cancer continues to claim lives and adversely affects socio-economic development. Although combination therapies were anticipated to eradicate this disease, the resilient and restorative nature of cancers allows them to proliferate at the expense of host immune cells energetically. This proliferation is driven by metabolic profiles specific to the cancer type and the patient. An emerging field is exploring the metabolic reprogramming (MR) of cancers to predict effective treatments. This mini-review discusses the recent advancements in cancer MR that have contributed to predictive, preventive, and precision medicine. Current perspectives on the mechanisms of various cancer types and prospects for MR and personalized cancer medicine are essential for optimizing metabolic outputs necessary for personalized treatments.

PRMT6 Epigenetically Drives Metabolic Switch from Fatty Acid Oxidation toward Glycolysis and Promotes Osteoclast Differentiation During Osteoporosis

Epigenetic regulation of metabolism profoundly influences cell fate commitment. During osteoclast differentiation, the activation of RANK signaling is accompanied by metabolic reprogramming, but the epigenetic mechanisms by which RANK signaling induces this reprogramming remain elusive. By transcriptional sequence and ATAC analysis, this study identifies that activation of RANK signaling upregulates PRMT6 by epigenetic modification, triggering a metabolic switching from fatty acids oxidation toward glycolysis. Conversely, Prmt6 deficiency reverses this shift, markedly reducing HIF-1α-mediated glycolysis and enhancing fatty acid oxidation. Consequently, PRMT6 deficiency or inhibitor impedes osteoclast differentiation and alleviates bone loss in ovariectomized (OVX) mice. At the molecular level, Prmt6 deficiency reduces asymmetric dimethylation of H3R2 at the promoters of genes including Ppard, Acox3, and Cpt1a, enhancing genomic accessibility for fatty acid oxidation. PRMT6 thus emerges as a metabolic checkpoint, mediating metabolic switch from fatty acid oxidation to glycolysis, thereby supporting osteoclastogenesis. Unveiling PRMT6's critical role in epigenetically orchestrating metabolic shifts in osteoclastogenesis offers a promising target for anti-resorptive therapy.

Non-metabolic enzyme function of pyruvate kinase M2 in breast cancer

Breast cancer (BC) is a prevalent malignant tumor in women, and its incidence has been steadily increasing in recent years. Compared with other types of cancer, it has the highest mortality and morbidity rates in women. So, it is crucial to investigate the underlying mechanisms of BC development and identify specific therapeutic targets. Pyruvate kinase M2 (PKM2), an important metabolic enzyme in glycolysis, has been found to be highly expressed in BC. It can also move to the nucleus and interact with various transcription factors and proteins, including hypoxia-inducible factor-1α (HIF-1α), signal transducer and activator of transcription 3 (STAT3), β-catenin, cellular-myelocytomatosis oncogene (c-Myc), nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB), and mammalian sterile 20-like kinase 1 (MST1). This interaction leads to non-metabolic functions that control the cell cycle, proliferation, apoptosis, migration, invasion, angiogenesis, and tumor microenvironment in BC. This review provides an overview of the latest advancements in understanding the interactions between PKM2 and different transcription factors and proteins that influence the initiation and progression of BC. It also examined how natural drugs and noncoding RNAs affect various biological processes in BC cells through the regulation of the non-metabolic enzyme functions of PKM2. The findings provide valuable insights for improving the prognosis and developing targeted therapies for BC in the coming years.

Epigenetic modulations in triple-negative breast cancer: Therapeutic implications for tumor microenvironment

Triple-negative breast cancer (TNBC) is an aggressive subtype lacking estrogen receptors, progesterone receptors and lacks HER2 overexpression. This absence of critical molecular targets poses significant challenges for conventional therapies. Immunotherapy, remarkably immune checkpoint blockade, offers promise for TNBC treatment, but its efficacy remains limited. Epigenetic dysregulation, including altered DNA methylation, histone modifications, and imbalances in regulators such as BET proteins, plays a crucial role in TNBC development and resistance to treatment. Hypermethylation of tumor suppressor gene promoters and the imbalance of histone methyltransferases such as EZH2 and histone deacetylases (HDACs) profoundly influence tumor cell proliferation, survival, and metastasis. In addition, epigenetic alterations critically shape the tumor microenvironment (TME), including immune cell composition, cytokine signaling, and immune checkpoint expression, ultimately contributing to immune evasion. Targeting these epigenetic mechanisms with specific inhibitors such as EZH2 and HDAC inhibitors in combination with immunotherapy represents a compelling strategy to remodel the TME, potentially overcoming immune evasion and enhancing therapeutic outcomes in TNBC. This review aims to comprehensively elucidate the current understanding of epigenetic modulation in TNBC, its influence on the TME, and the potential of combining epigenetic therapies with immunotherapy to overcome the challenges posed by this aggressive breast cancer subtype.

A Metabolic-Epigenetic Mechanism Directs Cell Fate and Therapeutic Sensitivity in Breast Cancer

Over the past decade, studies have increasingly shed light on a reciprocal relationship between cellular metabolism and cell fate, meaning that a cell's lineage both drives and is governed by its specific metabolic features. A recent study by Zhang and colleagues, published in Cell Metabolism, describes a novel metabolic-epigenetic regulatory axis that governs lineage identity in triple-negative breast cancer (TNBC). Among the key findings, the authors demonstrate that the metabolic enzyme pyruvate kinase M2 (PKM2) directly binds to the histone methyltransferase enhancer of zeste homolog 2 (EZH2) in the nucleus to silence expression of a set of genes that includes the mitochondrial carnitine transporter SLC16A9. Perturbation of this metabolic-epigenetic regulatory mechanism induces a metabolic shift away from glycolysis and toward fatty acid oxidation. The ensuing influx of carnitine facilitates the deposition of the activating epigenetic mark H3K27Ac onto the promoter of GATA3, driving a committed luminal lineage state. Importantly, this metabolic-epigenetic axis represents a potentially targetable vulnerability for the treatment of TNBC, a subtype that currently lacks effective therapeutic strategies. These findings lend further support for the paradigm shift underlying our understanding of cancer metabolism: that a cellular fuel source functions not only to provide energy but also to direct the epigenetic regulation of cell fate.

Exploring the diverse role of pyruvate kinase M2 in cancer: Navigating beyond glycolysis and the Warburg effect

Pyruvate Kinase M2, a key enzyme in glycolysis, has garnered significant attention in cancer research due to its pivotal role in the metabolic reprogramming of cancer cells. Originally identified for its association with the Warburg effect, PKM2 has emerged as a multifaceted player in cancer biology. The functioning of PKM2 is intricately regulated at multiple levels, including controlling the gene expression via various transcription factors and non-coding RNAs, as well as adding post-translational modifications that confer distinct functions to the protein. Here, we explore the diverse functions of PKM2, encompassing newly emerging roles in non-glycolytic metabolic regulation, immunomodulation, inflammation, DNA repair and mRNA processing, beyond its canonical role in glycolysis. The ever-expanding list of its functions has recently grown to include roles in subcellular compartments such as the mitochondria and extracellular milieu as well, all of which make PKM2 an attractive drug target in the pursuit of therapeutics for cancer.